CHEMISTRY COMES ALIVE
Chapter 2
Definition of Concepts
Matter = anything that occupies space and
has mass.
Solid
Liquid
Gas
Energy = the ability to do work
Potential energy
Kinetic energy
COMPOSITION OF MATTER
Matter is composed of
elements, 92 of which
occur naturally.
Elements cannot be
broken down or subdivided
by ordinary chemical
means.
98% of the body is
composed of the elements
CHNOPS
COMPOSITION OF MATTER
Atoms = smallest indivisible unit of an
element.
Molecule = two or more atoms of the
same element held together by chemical
bonds
Compounds = two or more atoms of
different elements held together by
chemical bonds.
ATOMIC STRUCTURE
PLANETARY MODELS
PERIODIC CHART
INERT ELEMENTS
ACTIVE ELEMENTS
RULES OF BONDING
Atoms in the periodic chart are said to be
neutral atoms = that is they have no
charge because they possess the same
number of protons (+) as electrons (-).
Ions = charged particles because of
uneven numbers of protons and electrons.
– Cation = positively charged
– Anion = negatively charged
IONIC BONDS
COVALENT BONDS
COVALENT BONDS
COVALENT BONDS
POLAR versus NON-POLAR
HYDROGEN BONDS
BIOLOGICALLY IMPORTANT
COMPOUNDS
Inorganic compounds = those that lack
carbon such as water, salt, hydrochloric
acid, etc.
Organic compounds = those that contain
carbon such as carbohydrates, lipids,
proteins, etc.
INORGANIC COMPOUNDS
Water is the most
important biological
inorganic compound.
–
–
–
–
Polar
High heat capacity
High heat of vaporization
Exhibits adhesion and
cohesion
– Liquid water is denser than
solid water
– Cushioning
INORGANIC COMPOUNDS
Electrolytes = any
substance that
disassociates in solution
to form ions that are able
to conduct electrical
currents.
–
–
–
–
–
Salts
Bases
Neutrals
Acids
Buffers
SALTS
Electrolyte that disassociates to form two
of the most notable ions in current
conduction.
NaCl
Na+ + Cl-
ACIDS
Release H+ ions
Considered to be proton donors
pH of less than 7.0
Example:
HCl
H+
+
Cl-
BASES
Release OH- ions
Considered to be proton acceptors
pH greater than 7.0
Example:
NaOH
Na+
+
OH-
BUFFERS
Buffers resist abrupt and large swings in
pH of body fluids by releasing hydrogen
ions when pH begins to rise and also
binding hydrogen ions when pH begins to
fall.
HCl + NaHCO3
NaOH + H2CO3
H2CO3 + NaCl
NaHCO3 + H2O
ORGANIC COMPOUNDS
Organic compounds contain carbon units put
together by covalent bonds.
There are four types of organic compounds:
– Carbohydrate
– Lipid
– Protein
– Nucleic acid
CARBOHYDRATES
CARBOHYDRATES
CARBOHYDRATES
LIPIDS
LIPIDS
LIPIDS
PROTEINS
PROTEINS
PROTEINS
PROTEINS
NUCLEIC ACIDS
NUCLEIC ACIDS